Sound box for talking machines



H. Y. PRENDERGAST. SOUND BOX FOR TALKING MACHINES. APPLICATION FILED 050 22. 1919. RENEWED JULY 8. 1921.

Patented Mar. 7, 1922.

lli lll ijft lH ll l I UNITED STATES PATENT OFFICE.

HAROLD Y. rnnnnnnsnsr, or BROOKLYN, NEW YORK;

SOUND BOX FOR TALKING MACHINES.

Specification of Letters Patent. Patented M 7 1922;

'Continuation of application Serial No; 134,987, filed December 4., 1916. This application filed December 22, 1919, Serial No. 346,750.

To all whom it may concern:

Be it known that I, HAROLD Y. PRENDER- GAST, a citizen of the United States, residing in the city of New York, borough of Brooklyn, county of Queens, and State of New York, have inventeda certain new and useful Sound Box for Talking Machines, of which the following is a specification.

This invention relates to improvements in sound'boxes, and is a continuation of my abandoned application, Serial Number 134987, filed December 1, 1916.

One of the objects of the invention is the provision of means for concentrating the sound waves emanating from the diaphragm, and conveying such sound waves through a passage so arranged as to preclude difliusion of extemporaneous sound waves in ad acent passages or chambers within the sound box.

A further object of the invention is to provide a means for taking the sound vibrations from the central portion of the diaphragm where the clearer and richer tones are. reproduced, and subsequently transmit such sound waves through an insulated passage to thetone arm. 1

Another object of the invention resides in the provision of a resilient enclosed partition or sounding board, so disposed and arranged to improve the quality of the reproduced sound.

A still further object of-the invention is the provision of a sound box provided with' means for concentrating the reproduced sound waves at or about the center of the diaphragm, and transmitting same to an.

outlet opening located eccentrically with reterence to the axis of the sound box.

The invention also comprehends improvements in the details of construction and arrangement of parts, which will be hereinafter described and particularly pointed out in the claims.

In the accompanying drawings:

Fig. 1 isa central section through a sound box embodying the present invention.

Fig. 2 is a section on the line 2-2 of Fig. 1.

Fig. 3 is a section on. the line 3-3 of Fig. 1, looking in the directionott' the diaphragm; and

Fig. 4 is a section on the line 3-3 of Fig. 1, looking in the direction of the tone arm.

In the drawings, a sound box is shown as embodying an annular casing 5 open at its Renewed July 8, 1921.

Serial No. 483,344.

front, but closed at its back by a platej 6,

be formed integral with the casing as shown or separately therefrom when desired, and.

spaced from'the forward face of this partition 9 is a diaphragm 10. The diaphragm 10 is secured at its outer periphery between the rings 11 and 12 preferably of rubber, the ring 11 resting on a shoulder 13 adjacent the margin of the partition 9 and the ring 12 being forced down uponthe' diaphragm by means of a two :part clamping ring composed otannular section'sla and 15. The section 15 rests upon the ring 12and the section 14 is exteriorly threaded and cooperates with interior threads in the casing-5, sothat when screwed down, it forces the section 15 agamst the ring 12 and clamps the diaphragm in place. Associated'with the diaphragm 10 is a stylus bar 16 secured to the diaphragm and mounted on the casing 5 in any suitable manner.

As stated, the diaphragm 10 and partithrough the aperture 18into the space intermediate the partition 9 andfthe back plate 6. I

It is desired that the sound waves passing from the sound chamber 17 through the-outlet 18 be communicated directly to the outlet passage in the boss 8 of the sound box,

and in order that such sound waves may. not be dissipated or diffused within the space 20 adjacent the back plate, the outlet 18 of the sound chamber and the outlet of the sound box are connectedby a passage which is walled oil from said space '20 of the chamber interiorly of the back plate. This feature is accomplished by positioning one or more elongated rings 19 of resilient material between the back plate 6 and the resilient partition 9, as shown in the drawings.- These'rings are preferably ofrubber 7 but, in any instance, are resilient, yielding or flexible- -When"disposed, as shown, they form a passage which collects the sound waves. at the outlet 18, of the sound chamber 17, andconveys said soundwaves d1+ rectl to the outlet of the sound box with whic is associated the tone arm; The object, in making the rings 19 of yielding, resilient or flexible character, is toinsulate the sound passage without interference with the vibration of the partition 9, if employed as a. sounding" board and also to preclude rattling or metallic sounds as would be the case ifthe rings 19 were of hard metallic character. .In order to hold the insulating wall or rings 19 in place, a flange 20 may be formed on the plate 6, although this flange may extend from the partition 9, if desired. The sidereaches of the insulating wall 19 are preferably spaced apart a distance substantially equal to the diameter of theoutlets of the sound chamber and sound box, while said wall is sufficiently extensive to. includethe remote end ofsaid outlets. It, will thus be manifest that the insulating wall 19 forms an insulating passage from the, outlet 18 to theoutlet in the boss 8 and does not allowthe dissipation of sounds-in the space 20. between the back plate 6 and the partition 9. Furthermore, it will be evident that the insulated passage, when asso ciated with the central opening, concentrates the sound waves and insulates same from the extemporaneous sounds in the chamber 20 It is evident that by the construction described, the effective sound waves are collected, and amplified by the resiliency of the partition 9, and are transmitted through a zone which preserves the quality and de-- livers such waves to the tonearm'.

Having thus fully described the invention, what I claim, as new and desire to secure by Letters Patent is 1. A sound box comprising a casin means extending across thecasing and dividing the same into diaphragm and, insulating chambers, adiaphragm in the diaphragm chamber, and a constricted passage of insulating material leading from an aperture in the dividing means to an aperture in the wall 7 of the insulating chamber positioned out of alinement with the aperture in the'dividing means.

2. A talking machine, a tone arm in combination with a sound box divided to form a diaphragm chamber at oneside thereof and an insulating chamber at the other side thereof, a diaphragm in the diaphragm "to the outlet olthe sound box to provide chamber and an insulating'passage in the insulating chamber which chamber extends in parallel relation to the diaphragm and has an entrance to the diaphragm chamber centrally thereof, and an outlet to the tone arm, adjacent the periphery of the sound box.

In a talking machine, atone arm in combination with-asoundbox divided by a centrally apertured sounding board to form a diaphragm chamber atone side'thereof and an'insulating chamber at the other side thereof, said insulating chamber having an outlet communicating with the tone arm eccentrically of the box, a diaphragm in the diaphragm chamber and an insulating passage leading from the central aperture of the sounding board tothe outlet to the tone arm. A i i 7 4.111 a talking machine, the combination with a tone arm of a sound box associated with the tone arm oil center,,said sound box being provided with a diaphragm, a soundingboard positioned intermediate'the diaphragm and the back of the-sound box and provided with acentral opening, and a passage leading from the central opening of the sounding board to the oil center tone arm and of lessarea thanthe chamber intermediate the" sounding board and the back of the sound box. i

5. A sound box embodying a casing,one side of which is closed by aback plate, a diaphragm and a sounding board "peripherally held within the casing inspa'ced relation to one another and to the back plate to form asou'nd chamber intermediate the diaphragm and the, sounding board, which sounding board is provided with'a central sound outlet of appreciably less-cross sectionalarea than the area of the sounding boardand theback plate being provided with an ofi center sound outlet, in combina- .back thereof, and a resilient, yielding and tion with an insulating sound duct extend flexible sound wall duct forming a passage way from the outlet of the sound chamber an exit for sound from the sound chamber opposite the zone of greatest amplitude of vibration ofthe diaphragm.

7. Asound box embodying a casing diside, a diaphragm in said diaphragm chamher and an insulating passage in and of less area than the second mentioned chamber and communicating with the diaphragm cham her.

8. A sound box embodying a casing divided to form a diaphragm chamber at one side and an insulating chamber at the other side, a diaphragm in said diaphragm chamber and an insulating passage in the second mentioned chamber, the longitudinal axis of which is parallel with the diaphragm, said passage having its entrance centrally ot' the sound box and its outlet adjacent to the periphery for communicating with a tone arm.

9. A sound box for talking machines, comprising a casing, a diaphragm arranged therein, a partition wall extending across the sound box and having an opening therethrough substantially centrally of the casing, and a restricted passage formed by walls projecting into the space between the partition wall and the rear wall of the casing and leading from said opening toward the peripheral portion of the casing, said pas sage having its outlet at said peripheral portion.

10. A sound box for talking machines, comprising a casing open at one side and closed at the other, a diaphragm arranged in spaced relation to the closed side, means dividing the box into a diaphragm chamber and an insulating chamber, a narrow walled passage in the last mentioned chamber leading from the central portion of the casing, and insulating means surrounding the wall of the said passage for insulating the sounds from and preventing the difiusion of the vibrations to the walls of the casing.

11. A sound box for talking machines, comprising a casing, a diaphragm arranged therein, a closure for one side of said casing spaced from said diaphragm, a partition in.- termediate the diaphragm and the closure, a wall between the partition and the closure to form a sound conveying passage, and concentrating means surrounding the walls of said passage and in contact with the closure for isolating the sound waves from the diaphragm.

12. A sound box for talking machines, having a sounding board between the diaphragm and sound outlet, and means for confining the sound between said sounding board .and outlet to an area substantially less than that of the sounding board.

13. A sound box for talking machines, having a sounding board between the diaphragm sound outlet, and an insulating soimd-confining member arranged between the sounding board and outlet.

14. A sound box for talking machines, having a sounding board between the diaphragm and sound outlet, and an insulating ring-like member including within its outline a portion of the area of the sounding board and the sound outlet.

15. A sound box for talking machines, having a sounding board between the diaphragm and sound outlet, and means for dividing the maximum and minimum vibrations of the diaphragm and delivering such maximum vibrations to the sound outlet.

16. A sound box comprising a casing having a resilient sounding board, adiaphragm resiliently spaced from the sounding board, and an insulating chamber at the opposite side of the sounding board and through which the sound passes to atone arm. v

17. A sound box comprising a casing, having a resilient sounding board, a dia phragm resiliently spaced from the sounding board, and a chamber formed on the opposite side of the sounding board and through which the sound waves from the diaphragm and the sounding board pass to a tone arm, said latter chamber being formed by resilient means interposed between and bearing on the casing and the sounding board.

In testimony whereof, I have signed my name to this specification.

HARGLD Y. PRENDERG-AST. 

